Steam-engine.



W. RANFT.

STEAM ENGINE.

APPLICATION FILED FEB. |914.

Patented July 3, 1917.

fill/IIIA ITED STEAM-ENGINE.

Laaaoss.

To all whom it may concern:

Be it known that I, WALTER RANFT, citi- Zen of the German Empire, residing at 45 Freibergerstrasse, Dresden -A. 4, Germany, have invented an Improved Steam- Engine, of which the following is a specification.

This invention relates to steam engines in which the steam lis generated within the engine cylinder without the employment of a steam boiler.

In this type of steam engine it is already known to spray the water to be evaporated onto an externally heated plate, so that it is vaporiz'ed or split up into its constituents according to the degree of heating.

It has also been proposed to supply the water to a pocket in the piston, the water being preliminarily heated by contact with the cylinder wall during the inward stroke and thereupon entering an enlarged externally heated cylinder head in which the vaporization takes place. By these methods, however, the vaporization takes place too slowly for practical purposes, and if the intensity of heating is increased the vaporization is still further retarded by the formation of so-called Leidenfrost drops, an isolating film of steam surrounding the water drops and preventing the conductivity of heat.

According to the present invention this formation of Leidenfrost drops is intentionally effected by sufficiently highly heating the cylinder head, but, on the other hand, the stroke of the piston is so measured that the water drops resulting from the heating of the cylinder head are destroyed by the piston during its inward stroke, the stroke of the piston being such that it approaches the cylinder head to such an extent as to strike the water drops. In this manner the water drops are, as it were, caused to explode, that is to say instantaneous vaporization takes place, driving the piston outwardly under a high initial pressure and with a correspondingly high acceleration. In this manner a'high .speed steam engine is obtained.

i It will be seen from the foregoing that two conditions must be fulfilled Firstly sufficiently high heating so that immediate or slow vaporization does not take place but so that so-called Leidenfrost drops are formed `and Secondly the destruction of these drops so Specification of Letters Patent.

Application led February 7, 1914.

raten-teu muy e, reir.

Serial No. 817,375. y

that they are not ,left to themselves so as to deteriorate the vaporization, but caused to immediately vaporize after the manner of an explosion by their destruction.

A further object of the present invention consists in the construction of the driving parts of the steam engine, that is to say, the cylinder, piston and piston rod, for the purpose of avoiding impacts and more efficiently carrying out the invention already set forth.

For this purpose the cylinder head is drawn o-ut into the form of a conical end and the piston correspondingly shaped so as to fit the conical end of the cylinder. This prevents the injected water from covering too large a surface and from consequently rapidly cooling the end of the cylinder, and in consequence thereof the end of the cylinder is rapidly heated up again after each explosion. Moreover, the conical end of the piston does not strike the water drops simultaneously but crowds the water from the peak of the cone toward the sides thus distributing the water drops uniformly over the conical part of the cylinder. By this means the impact is diminished and the water distributed as a very thin layer over the conical end of the cylinder so that the heating action of the cylinder end is more intensive. The steam suddenly generated by the impacts is subjected to a comparatively steadily maintained subsequent heating, since the distance between the piston and the cylinder end increases more gradually in the case ofa conical form than in the case of a flat piston and cylinder end. The piston and cylinder end may be accurately fitted to one another or so formed that in the heated state the surfaces fit each other, -so that practically no clearance is provided when the piston is in its innermost position. Firing up is preferably effected when the piston is in this position, so that it is also heated and when it has attained a temperature of 300 to 500 C., the crank shaft is set in rotation and water injected into the cylinder. As soon as the piston attains its innermost position it distributes the water Within the heated clearance space and the explosion resulting from the destruction of the water drops drives the piston outwardly. The loss of heat consequent thereon being in ,fthe meantime made good.

A further object of the present invention is to prevent breakage of the parts, should the initial impact be excessive and for this purpose a device is provided between the piston andv the crank shaft for reducingk the impact, this preferably comprising a strong spring in the piston rod.

In order that the inventlon may be more clearly understood reference is made to the 'accompanying drawings showing various embodiments of the invention b-y way of example. j

Figures 1 and 2 are vertical sections 'at right angles to each other through avertical steam engine constructed according to the present invention.

Fig. 3 isa vertical section showing an inclined steam engine which is particularly applicable for marine purposes owing to the reduced height.

Fig. 4 is a vertical sectional detail view of the impact absorber fitted upon the piston ro The furnace a is Aarranged beneath the cylinder "b of the steam engine which is surrounded by brick setting d and an ex- As shown on f' ternal protecting casing c. the drawings a flue e preferably surrounds the-cylinder, so that the furnace gases pass around the cylind'eriand'pass to the uptake f through the outlet y'. The cylinder b is pro- SO/Vided with an exhaust port f controlled by means of a valve f and water is adapted to be injected into the. cylinder through a passage g communicating with a water pump le. controlled from the crank shaft w through the medium of a governor z' and intermediate transmission gearing. The lower end of the cylinder b is shaped t-o form a conical'end p and the piston n is formed with a corresponding conical end m. The piston rod o is articulated to the piston n by means of a bolt g in the usual manner and transmits motion to the crank shaft w through the impact absorbing device illustrated in detail in Fig. 4. As shown in this ligure, the piston rod is recessedl to receive a spiral spring rbearing at one end against' the lshoulder of the recess and at the other end against a thimblel k screwed upon a spindle Z sliding in t he recessed end of the piston rod v0 and carried bythe strap s. Bolts t on the strap s pass through a flange 'n in the end ofl a piston rodo and enable the length of the piston rod connection to -be adjusted so'that, if desired, the piston may strike the end p of the cylinder beforel reaching its dead point thereby advancing the stroke of the piston. It is clear that in this manner the steam engine may be regulated by controlling Athe instant of the explosion.

The cylinder end p being highly heated, Leidenfrost drops will be generated on injecting water through the, passage g, `these Water drops being destroyed toward the end of the instroke of the piston n by contact with they conical piston end` m causing imme-v diate steam generati-on in the manner of 'an explosion and driving the piston outwardly. The exhaust valve f may be controlled in a suitable manner from the crank shaft w by means of a valve rod u. Y

The modification illustrated in Fig. 3 is the same in vprinciple 4as the steam engine shown in Figs. 1 and 2, theconical cylinder.

` of the acting face of the piston exactly cor-l responding to that of the cylinder bottom and the stroke of the piston being such that at the end of its instroke it destroys said Leidenfrost drops between it -and the bottom of the cylinder, and thereby effects thev sudden generation of steam.

2. A steam engine 1n which thesteam is .generated within the engine cylinder comprising a cylinder, vmeans for injecting i .water into the cylinder, means for externally heating one end'of said cylinder to cause the formation of Leidenfrost drops, a piston in said cylinder adapted on its instroke to destroy said drops and thereby effect the sudden generation of steam, a crank shaft, a piston rod connecting said piston and crank shaft and an impact absorber intermediate said piston and crank shaft and through which motion is transmitted to the crank shaft.

3. A steam engine in which the steam is 'generated within the engine cylinder comprising a cylinder, means for injecting water into the cylinder, means for externally heating one end of said cylinder to cause the formation of lLeidenfrost drops, a piston in said cylinder adapted on its in-4 stroke to 4destroy said drops and thereby effect the sudden generation of steam, ,a crank 1 shaft a piston rod connecting said piston and crankshaft and an impact absorber onA the crank shaft end of said piston rod.

4. In a steam engine of the class in which y steam is generated Within the engine cylinder, the 'combina-tion of a cylinder having inlet and outlet ports' and a section which tapers longitudinally and -is closed at its small end, means for injecting water into the cylinder, means for externally' heating the tapered section ofthe cylinder to such a temperature as to cause the water to form -Leidenfrost drops therein, and a recziprocat-v ing piston hvng a t'pefred end correspond. ing closely in form and size to the ililteror of the tapered section ofthe cylinder, the

'parts being so proportioned that at the end of its hstroke the piston will destroy the Ledenfr'ost drops betweenJ it Vamd the cylinder, forthe purpose described.

l 1,232,083 v e signatureln presence of VtWo Witnesses.

y WALTER RANFT.

Witnesses:rv y

A. Gr. BUCHANAN, l v t LEO BERGHoLz.

testimony whereof I have avxed lily F' 

